Dehydration
Conditions
Brief summary
It is well-established that exercise has many health benefits. During exercise in temperate/hot conditions, sweating is necessary to dissipate heat. This sweating typically results in dehydration, which may impair physical and mental performance. Therefore, following exercise, effective rehydration is important to restore an optimal hydration state and therefore physical and mental performance. If an individual only rehydrates with water, though, it is unlikely that they will fully rehydrate as plain water is not very well-retained by the body, due to its lack of carbohydrate and electrolytes. For this reason, sports/ hydration drinks are likely to aid in better rehydration, due to their carbohydrate and electrolyte content. This project aims to compare the rehydration effectiveness and glucose responses to two sports / hydration drinks and water (with different carbohydrate and electrolyte contents).
Interventions
OTHERWater
Consumption of a water volume (from water) equal to 150% of body mass loses from exercise-induced hypohydration
Consumption of a water volume (from a glucose-based sports drink) equal to 150% of body mass loses from exercise-induced hypohydration
OTHERFruit beverage
Consumption of a water volume (from a fruit beverage) equal to 150% of body mass loses from exercise-induced hypohydration
Sponsors
Nottingham Trent University
Innate-Essence Limited
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
\- Training/performing \> 1 hrs a week
Exclusion criteria
* Smoker. * Pregnant, attempting to become pregnant, or breastfeeding. * Diabetic. * You have adverse events/reactions in response to fingertip capillary blood sampling which includes, but is not limited to; fainting and/or serious bruising. * History of heat-related illness. * History of heart failure, pulmonary hypertension, embolism, or other pulmonary heart disease. * Previously diagnosed with COPD, emphysema, bronchitis or similar respiratory illness. * Have a history of severe allergic reactions. * History of kidney issues. * Regular use of non-steroidal anti-inflammatory medications. * Any other medical conditions / medications that may interfere with an individuals ability to safely perform exercise in the heat and experience dehydration. * Allergies/intolerances to any of the following ingredients: Glucose Syrup, Acid (Citric Acid), Acidity Regulator (Sodium Citrate), Extract of Black Carrot, Watermelon, pomegranate, lime, Preservatives (Potassium Sorbate, Dimethyl Dicarbonate), Stabilisers (Acacia Gum), Sweeteners (Aspartame, Acesulfame K), Antioxidant (Ascorbic Acid), Flavourings, Niacin (Vitamin B3). * Elite athlete subject to doping tests
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Net water Balance | Baseline (pre-exercise), post-exercise, and 0, 1, 2, 3, and 4 h post-rehydration | (\[post-exercise body mass (kg) - Pre-exercise body mass (kg)\] x 1000) + water volume consumed (g) - cumulative urine output during rehydration period (g) |
| Cumulative urine volume | 0, 1, 2, 3, and 4 h post-rehydration | — |
| Total urine volume | Sum of urine produced at 0, 1, 2, 3, and 4 h post-rehydration | Total urine volume produced during the rehydration period |
| Water retention | 4 h post-rehydration | (\[water volume consumed (g) - total urine volume produced during the rehydration period (g)\] / water volume consumed (g)) x 100 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Blood glucose concentration | Baseline (pre-exercise), post-exercise, and 0, 0.25, 0.5, 0.75, 1, 1.5, and 2 h post-rehydration | — |
| Blood glucose area under the curve | The 2h period following rehydration | — |
| Hyperglycaemia incidence | The 2 h period following rehydration | Number of participants that experience blood glucose \> 7.8 mmol/L |
| Hypoglycaemia incidence | The 2 h period following rehydration | The number of participants that experience blood glucose \< 3.9 mmol/L |
| Urine osmolality | Baseline (pre-exercise), post-exercise, and 0, 1, 2, 3, and 4 h post-rehydration | A measure of urine concentration. |
| Body mass | Baseline (pre-exercise) and post-exercise (approximately 2 h post-baseline, depending on sweat losses during cycling in the heat) | Body mass in kilograms at baseline compared across trials. Body mass loss (both in grams and as a percentage) from pre-exercise to post-exercise compared across trials. |
| Thirst | Baseline (pre-exercise), towards the end of each 10 minute block of exercise (cycling in the heat), post-exercise, and 0, 1, 2, 3, and 4 h post-rehydration | Participants asked to rate their thirst on a scale of 0-10 (0 = no symptom, 10 = maximum symptom) |
| Gastrointestinal comfort | Baseline (pre-exercise), post-exercise, and 0, 1, 2, 3, and 4 h post-rehydration | Participants asked to rate their gastrointestinal comfort on a scale of 0-10 (0 = no symptom, 10 = maximum symptom) |
| Rating of perceived exertion (RPE) | Measured towards the end of each 10 minute block of exercise (cycling in the heat). Up to 8 blocks lasting a total of 120 minutes (10 minutes of cycling, followed by 5 minutes of rest), depending on body mass loss. | Participants asked to rate their RPE on a scale of 6-20. This is a measure of exercise intensity. Average taken for dehydration period. Average compared across trials. |
| Thermal sensation | Measured towards the end of each 10 minute block of exercise (cycling in the heat). Up to 8 blocks lasting a total of 120 minutes (10 minutes of cycling, followed by 5 minutes of rest), depending on body mass loss. | Participants asked to rate their thermal sensation on a scale of -10 (unbearably cold) to 10 (unbearably hot). Average taken for dehydration period. Average compared across trials. |
| Time in environmental chamber | Up to 120 minutes, depending on body mass losses during cycling in the heat | The time in minutes that the participant spent in the environmental chamber at 35 degrees Celsius, doing repeated blocks of 10 minutes of cycling followed by 5 minutes of rest, until they reached approximately 1.5% body mass loss. Time compared across trials. |
| Laboratory temperature | Baseline (pre-exercise), post-exercise, and 0, 1, 2, 3, and 4 h post-rehydration | Temperature (degrees Celsius) of the laboratory measured across the day and averaged. Averages compared across trials. |
| Environmental chamber temperature | Measured towards the end of each 10 minute block of exercise (cycling in the heat). Up to 8 blocks lasting a total of 120 minutes (10 minutes of cycling, followed by 5 minutes of rest), depending on body mass loss. | Environmental chamber temperature (degrees Celsius) measured and averaged for the cycling in the heat period of each participant. Averages compared across trials. |
| Laboratory humidity | Baseline (pre-exercise), post-exercise, and 0, 1, 2, 3, and 4 h post-rehydration | Humidity (relative humidity) of the laboratory measured across the day and averaged. Averages compared across trials. |
| Environmental chamber humidity | Measured towards the end of each 10 minute block of exercise (cycling in the heat). Up to 8 blocks lasting a total of 120 minutes (10 minutes of cycling, followed by 5 minutes of rest), depending on body mass loss. | Environmental chamber humidity (relative humidity) measured and averaged for the cycling in the heat period of each participant. Averages compared across trials. |
Countries
United Kingdom
Outcome results
None listed